<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>页面布局</title>
</head>


<body>
    <style>
        div{
            width: 100%;
            height: 150px;
            background-color: red;
            display: flex;
            justify-content: space-around;

            align-items: center;

        }

        div>span{
            background-color: green;
            width: 100px;
        }

    </style>

    <div>
        <span>1</span>
        <span>2</span>
        <span>3</span>
    </div>


</body>
</html>